ExpressCard or Express Card?

So a co-worker recently asked an interesting question - is “expresscard” spelled correctly as one word or two words?

I did a little research and concluded that while ExpressCard is technically correct (see expresscard.org), Express Card is more commonly used online.

The introduction of the Express Card has already created a lot of unique problems for laptop users trying to figure out what peripherals will work with their stuff (see our Express Card to PCMCIA review) and apparently the technically correct spelling is just the tip of the iceberg.